MENDELIAN LAWS OF INHERITANCE 295 



(v) After dealing with peas varying in one pair of characters, 

 Mendel crossed varieties exhibiting two pairs of allelomorphs, 

 and determined the distribution of the parental features among 

 the offspring. 



When a round pea having green cotyledons is crossed with a 

 wrinkled one having yellow cotyledons, two allelomorphic pairs are 

 concerned, viz. (i) 'round' and 'wrinkled'; (2) 'yellow' and 

 ' green.' 



(i) 'Round' seeds are dominant to 'wrinkled' seeds; 



(2) ' Yellow ' cotyledons are dominant to 'green ' cotyledons. 



The first cross, or Fj generation, is found to consist of round, 

 yellow peas only. 



On self-fertilisation Fj generation is obtained. This yields 

 four types of peas, namely — 



1. Round yellow 



2. „ green 



3. Wrinkled yellow 



4. „ green 



in the following proportion ;- 



